September 22, 2012

ESHE 2012 abstracts

Some abstracts of interest from the European Society for the study of Human Evolution 2012 meeting (pdf). To avoid making this too long, I will just post the titles and the most relevant quotes. You can read the abstracts in the linked pdf for authors names and more information.

Neandertal
and Denisovan Genomes from the Altai

Susanna Sawyer et al.

In 2010 a draft genome sequence was determined from a small
finger bone found in Denisova Cave in southern Siberia. Its analysis revealed
that it derives from an individual who belonged to a population related to, but
distinct from, Neandertals. A molar has also been described from DenisovaCave and has shown to carry an mtDNA
genome closely related to that of the finger bone. We have recently
determined the DNA sequence of the Denisova genome to a quality similar to
present-day human genomes. We have also retrieved a complete mitochondrial
genome and nuclear DNA sequences from an additional molar found in DenisovaCave. Furthermore, we have determined a
high-quality nuclear genome from a pedal phalanx found in DenisovaCave
in 2010. We show that the pedal phalanx derived from a Neandertal and thus that
Neandertals as well as Denisovans have been present in the cave. We will
discuss the genetic history of Denisovans as well as Neandertals in light of
these new genome sequences.

The discovery of a Neandertal genome from Denisova cave is certainly interesting. I have previously commented that:

If Vindija and Denisova, two caves less than 5,000km apart were home to people more divergent from each other than any two humans are today, it's strange to think that only "modern humans" inhabited Africa at the same time.

Now, it appears that Neandertals and Denisovans were present (when?) not only 5Mm apart, but literally on the same spot. Much later, during the Neolithic we see very differentiated humans co-existing in Europe. And, we get archaic hominins in Africa long after the appearance of anatomically modern humans there. I think the evidence is looking good for my hypothesis that regional human populations have recently gotten more similar over time through extensive admixture between divergent hominin groups, rather than that they became more dissimilar over time through tree-like divergence.

On the same topic, here is more evidence for Neandertal presence in the Altai:

Both the mandible and the dentition preserve numerous derived Neanderthal traits: among else a posteriorly placed mandibular foramen, an oblique mylohyoid line, an asymmetrical P4 and continuous mid-trigonid crests on the M1 and M2. ... Ongoing ancient DNA analyses of the hominin remains from Chagyrskaya cave and absolute dates for the site will hopefully help to clarify the origin of the Altai Neanderthals, and their relationship with the Denisovans.

An hypothesis for the phylogenetic position of Homo ﬂoresiensis

Our cladistic analysis places H. ﬂoresiensis unequivocally as part of a clade with H. habilis

Who are you calling ”modern”? An assessment of the dental morphology and metrics of Homo sapiens

Although dental reduction has long been cited as a derived feature of H. sapiens, our data indicate this claim may be no longer tenable ... the single metrical assessment that groups all H. sapiens (early, Upper Paleolithic and recent) apart from other taxa is the ratio between mandibular:maxillary crown areas. the results of our study are important for assessing recent claims of great antiquity for H. sapiens outside of Africa

Neanderthal in Malthusian demographic trap

It can be hypothesized that the demography of the Neanderthal metapopulation, living under conditions where extreme environmental instability with short periods was the norm, was primarily stagnant,

with frequent bottlenecks and episodes of decline.

A New Framework for the Upper Paleolithic of Eastern Europe

The results
of field and laboratory research during the past decade require a new
classificatory framework for the Upper Paleolithic in Eastern
Europe. It is now apparent that people making artifacts assigned
to the Ahmarian industry occupied both the southern and northern slopes of the
Caucasus Mountains (i.e., Ortvale Klde, Layer 4d; MezmaiskayaCave,
Layer 1C). Their sites probably indicate a separate movement of anatomically
modern humans (AMH) from the Near East directly into Eastern Europe,
establishing an independent line of development during the earlier Upper
Paleolithic that parallels the Proto-Aurignacian and Aurignacian sequence in
Western and Central Europe. this East European industry is most fully
represented at the Kostenki-Borshchevo sites on the Don River before 40,000 cal
BP (e.g., Kostenki 14, Layer IVb). It is followed by a closely related
industry, also characterized by bladelet production, that is dated to the
interval between 40,000 and 30,000 cal BP in Crimea and the East European
Plain. The proposed new framework reflects recognition of these distinctive
East European entities and of two environmental events that had significant
impacts on human settlement in Eastern Europe: (1) the Campanian Ignimbrite
(CI) volcanic eruption (40,000 cal BP); and (2) the Last Glacial Maximum (LGM)
( 25,000 cal BP). It has been suggested that the early Upper Paleolithic (EUP)
industry present in Eastern Europe before 40,000 cal BP should be labeled an
eastern variant of the contemporaneous Proto-Aurignacian of Mediterranean
Europe. However, given the separate movement of people from the Near East via
the Caucasus Mountains, and independent development of the East European EUP,
this industry is more appropriately termed “Proto-Gravettian.” The younger bladelet
industry, which includes assemblages at Buran-Kaya III (Layer 6-1), Mira (Layer
II/2), Kostenki 8 (Layer II), and probably Shlyakh (Layers 4C, 6), may be
termed “Early Gravettian” to distinguish it from the classic Gravettian
industry that dates to less than 30,000 cal BP (e.g., Avdeevo, Zaraisk).The
upper temporal boundary of the Proto-Gravettian corresponds to the CI eruption (40,000
cal BP), while the classic Gravettian of the East European Plain appears to
have been effectively terminated by the LGM ( 25,000 cal BP). Several sites
that date to the 40,000–30,000 cal BP interval (e.g., Kostenki 1, Layer III)
contain elements that suggest a connection with the Aurignacian technocomplex
of Western-Central Europe. These assemblages may be placed into the category of
“Eastern Aurignacian,” which reflects differences in content with the West and
Central European sites. The apparent spread of this industry into Eastern Europe
from Central Europe may be related to the impact of the CI eruption on portions
of the East European Plain.

Conﬂicting dates for the Late Aterian

First at the huge Ifri n’Ammar sites, TL dates have indicated 80,000 years for the Late Middle Palaeolithic/Aterian levels. Our new C14 dates yield 35,000 BP for exactly the same levels. At the “grotte des Contrebandiers”, formerly dated at 28,000 BP by Debenath and his team, is now dated at 100,000 years by new TL dates. As starting points, this kind of methodological contradiction should be confronted, understood and resolved.

The Rio Secco Cave in the North Adriatic Region, Italy. A new context for investigating the Neanderthal demise and the settllement of Anatomically Modern Humans

A sequence of several thin layers dated to 46.0–42.1ky Cal BP represents the final Mousterian.

The Dhofar Nubian Tradition: an enduring Middle Stone Age technocomplex in southern Arabia

Between
2010 and 2012, the Dhofar Archaeological Project has located and mapped 260
Nubian Complex occurrences across the Nejd Plateau of southern Oman.
Diagnostic Nubian artifacts werefound cemented in fluvial sediments at the site
of Aybut Al Auwal in Dhofar, with two OSL dates around 106 ka BP; hence,
roughly contemporaneous with the African Nubian Complex (Rose et al. 2011).
Many of these lithic assemblages, such as that from Aybut al Auwal, are
technologically homologous to the Late Nubian Industry found in northeast Africa, sensu stricto, while others may represent local
facies of the greater “Afro-Arabian Nubian Technocomplex.” This presentation
describes the various reduction strategies encountered at a sample of Nubian
Complex sites from Oman,
explores inter-assemblage variability, and begins to articulate technological
units within the “Dhofar Nubian Tradition.” To achieve this aim, we have
developed an analytical scheme with which to describe technological variability
among Nubian Levallois reduction strategies in both Africa and Arabia. Our analysis indicates at least two distinct
Nubian industries. The first, which we refer to as the “Classic Dhofar Nubian,”
is virtually identical to Late Nubian Industry from the LowerNileValley
and Red Sea Hills in Egypt.
Thee subsequent group of assemblages in Dhofar, called the “Mudayyan,” exhibits
a technological shift toward diminutive Nubian Levallois cores and that,
recurrent bidirectional cores with opposed, faceted striking platforms. We
interpret this evidence to indicate an enduring, local Nubian tradition in
Dhofar that is ultimately rooted in the African Nubian Complex.

From Late Mousterian to Evolved Aurignacian: New evidence for the Middle-to-Upper Paleolithic transition in Mediterranean Spain

Combined, the evidence from CA and FDM indicates that, in chronostratigraphic terms, the Middle-to-Upper Paleolithic transition in Murcia consists of the replacement of a Late Mousterian by an Evolved Aurignacian and occurred some time during the 38th millennium cal BP

2 comments:

The H. ﬂoresiensis paper doesn't seem that surprising giving what we already knew about its post-cranial anatomy, however it still begs the question how H. habilis got all the way over to Indonesia and why we haven't seen any sign of it elsewhere in Asia.

We have the transitional Homo georgicus - if it can still be called that - which is somewhere "between" H. habilis and H. ergaster/erectus from Dmanisi in Georgia. It's dated 1.8 million years ago and on the border of Asia proper, there's little reason why it couldn't have gone farther in the east. With time, more findings could/should be found to fill the route, in space and time, from Georgian hominids to Homo floresiensis.

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